Record levels of soybeans are still in storage in Minnesota and across the U.S. after the fall harvest, thanks to the trade war with China, the U.S. Department of Agriculture said in a new report that was delayed by the government shutdown.

More than 3.7 billion bushels of soybeans were sitting in bins in the U.S., an 18 percent increase compared to a year earlier, the USDA's latest survey found.

More farmers are waiting out low prices and hoping for progress on trade talks with China rather than selling at a loss.

More than 339 million bushels of soybeans were in storage in Minnesota, the agency said, 10 percent more than a year ago.

"That sounds like a low estimate in my opinion," said Bob Zelenka, executive director of the Minnesota Grain and Feed Association. "Bottom line is there's still a lot of grain out there that needs to move."

Prices for soybeans fell at the start of last summer when President Donald Trump signaled his intent to launch a trade war, and they haven't recovered. The price per bushel has hovered around $9 since November.

Soybeans are Minnesota's largest agricultural export by far, with $2.1 billion in exports in 2016, more than double the value of exported corn.

Most of the soybeans in western and northwestern Minnesota are grown for sale to China.

Minnesota has more than enough room to store all the beans — about 600 million bushels of capacity at grain elevators and another 2 billion bushels on farms, where farmers have been building more and more bins over the past 20 years.

But as the warmer weather and the 2019 harvest approach, farmers will be eager to clear their bins, Zelenka said.

"We're used to moving beans in the fall and into early winter. Farmers need to be more vigilant in maintaining the quality of the grain they have on the farm," Zelenka said. "The advantage we have here is our winter. In terms of bug activity and mold, that's not a concern until it gets warmer."

Adam Belz is the agriculture reporter for the Star Tribune. He previously spent one-and-a-half years reporting at Minneapolis City Hall and four years covering economics. Before that, he reported for the Des Moines Register and Cedar Rapids Gazette.